Toshiba QLC 3D NAND squeezes a fourth bit into flash cells

Data density is critically important to manufacturers of flash storage chips. Increasing the number of bits in a given amount of die space allows for reduced manufacturing costs, potentially lower power requirements, and gets large amounts of information into ever-shrinking packages. Flash memory comes in flavors with a single bit per cell (SLC) to three bits per cell (TLC), and now Toshiba has announced that it has started manufacturing quad-level cell (QLC) 3D NAND chips. Like it says on the tin, these chips are capable of holding four bits per cell.

Toshiba's QLC chips are built on the company's BiCS 3D manufacturing technology, and the first dies out of the gate store 768 Gb (96 GB) each. The company says a package with a 16-die stack can store 1.5 TB. The previous-generation TLC technology could "only" pack 1 TB into the same package. In its press release, Toshiba touts the potential applications of these higher-density flash chips in datacenters, though it's not hard to imagine the technology trickling down into larger-capacity storage devices for mobile devices and PCs.

Toshiba says it started delivering sample QLC flash chips to SSD and SSD controller vendors earlier this month, and that some of the first silicon will be displayed at the 2017 Flash Memory Summit in August. There's currently no word on longevity and performance figures for the new chips, but the achieved density is impresssive on its own.